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OPERATIONS
AND
TIMING
B.
Outline
of Electric Circuitry
The
NP-1550's main
mechanisms
are
controlled
by
the
microprocessor,
PROM,
and
EEPROM
on
the
DC
controller
PCB.
1.
Microprocessor (Q303)
•
controls
the copying
sequence
•
controls the control
panel
•
controls the
main
motor/scanner motor
•
controls
the
scanning
lamp
•
reads
the
analog
signals
2.
PROM
(Q318)
•
contains the
sequence program
3.
EEPROM
(Q315)
stores
data
that
can be
modified
in
the
service
mode
(replaces conventional
variable resistors
and
switches)
-
|
*>*!;.....„i.v,.T
n .,.,,..-
„,..„„,,
.,
r
.,.,~
.,,
^EHPRGM'k
a
type
oT,rtQfvt:,W..w.hfcft"
.
datajrnay;tie
Erased
or
st^ftrfiply/.
,
,
.
'
'
For
this
reason, the
NP-1550's
RAM
and
RAM
are not
backed up
by
a
lithium
battery.
.W^™,,,,^:,,,^.^,
,.,./
,,,
,„,
-
.
The NP-1550
is
equipped
with
an
A/D
converter and,
therefore,
its
micro-
processor can read analog
signals.
Note:
The
main motor
(M1)
is
a synchronous
motor
that
uses
the
frequency
of
the
power
supply
as
the reference
of
its
operation.
The
scanner motor (M2)
are stepping
motor
that
use
the
oscillation
frequency
of
the
crystal oscillator
on
the
DC
con
trailer.
Fluctuations
of
the
frequency
in
the
power
supply during copying operation
^affects
only the
revolution
of
the
main
motor
(M1)
and
result
in
:expahsjdn;
s
Or
contraction
of
the
images.
V
!
?
3-2
COPYRIGHT©
1992
CANON
INC.
CANON
NP-1550
REM
JAN.1992 PRINTED
IN
JAPAN
(IMPRIME
AU JAPON)
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